What signal is typically used to indicate that the gangway is secured?

The correct signal to indicate that the gangway is secured is represented by a red flag or light. This signaling is part of standard maritime communication practices, and the use of red serves as a clear visual cue that the area is not open for passage. In a nautical environment, red is universally recognized as a color signifying danger or that an area is closed off, ensuring that personnel, including visitors and crew members, are aware that they should not attempt to board or disembark. This safety measure is critical in preventing accidents or unauthorized access, particularly in busy ports or while a vessel is in motion.

In contrast, other signals like a green flag or light typically symbolize that an area is clear and safe for passage, and a warning horn sound may indicate different operational statuses but is not specifically used for indicating gangway security. A yellow ribbon may indicate caution or a warning, but it does not have the clear, established meaning associated with securing the gangway. Thus, the choice of a red flag or light is aligned with established maritime safety protocols.